1. Field of the Invention
The present invention relates to a developing apparatus using a one-component developer and particularly to a one-component developing apparatus which includes a developer layer thickness regulating member for regulating the layer thickness of the one-component developer to be carried toward a latent image bearing member by a developer bearing member.
2. Description of the Related Art
In an image forming apparatus such as a copying apparatus, printer, etc., an electrophotographic system or an electrostatic recording system has widely been used as a recording system.
An image forming apparatus of such an electrophotographic system or an electrostatic recording system is provided with a developing apparatus which develops a latent image formed on a latent image bearing member such as a photosensitive material drum or dielectric material drum.
A one-component developing apparatus holds a one-component toner at its surface. The one-component developing apparatus includes at least a developing roller for transferring the toner and a layer thickness regulating blade which regulates the layer thickness of the one-component toner carried at the surface of the developing roller to a constant predetermined layer thickness. A latent image on the latent image bearing member is regulated in layer thickness by the layer thickness regulating blade and is developed by the one-component toner carried by the developing roller. The one-component toner is charged by a friction charge generated between the developing roller and the one-component toner or by a charge supplied from the blade which is connected with a power supply. Therefore, the developing operation can be carried out by adhering the toner on the latent image bearing member with electrostatic force being applied between the charged one-component toner and the latent image on the latent image bearing member.
In a one-component developing method using a one-component toner, the layer thickness (circumferencial direction and/or axial direction of the developing roller) of the one component toner carried by the developing roller has a substantial influence on the quality of image developed. The layer thickness of this one-component toner changes depending on the surface accuracy at a thickness-regulated surface of the layer thickness regulating blade, thus creating a problem. Namely, if the thickness regulating edge of the layer thickness regulating blade is formed with any unevenness, a vertical line appears on the developed image corresponding to such unevenness.